---
id: CVE-2026-70453
title: "rsync before 3.5.0\_contains an algorithmic complexity vulnerability in the hash_search() function that allows a remote attacker to cause a denial of service by delivering a carefully constructed file list"
summary: "rsync before 3.5.0\_contains an algorithmic complexity vulnerability in the hash_search() function that allows a remote attacker to cause a denial of service by delivering a carefully constructed file list. A sender can exploit the quadra…"
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'
cwe:
  - CWE-407
  - CWE-770
published: '2026-08-13'
updated: '2026-09-08'
sourceUpdated: '2026-09-08T20:28:37.587'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-70453'
references:
  - url: 'https://github.com/RsyncProject/rsync/releases/tag/v3.5.0'
    label: disclosure@vulncheck.com
  - url: >-
      https://github.com/RsyncProject/rsync/security/advisories/GHSA-8x5r-mjx8-83hv
    label: disclosure@vulncheck.com
  - url: >-
      https://www.vulncheck.com/advisories/rsync-algorithmic-complexity-dos-via-hash-search
    label: disclosure@vulncheck.com
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-70453.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-70453'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2515403'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-70453'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-70453'
  - url: 'https://access.redhat.com/errata/RHSA-2026:67463'
  - url: 'https://access.redhat.com/errata/RHSA-2026:67462'
tags:
  - nvd
  - csaf
  - vex
  - red-hat
epss: 0.0075
epssPercentile: 0.52947
ingestedAt: '2026-09-08T21:11:12.277Z'
vendor: Red Hat
product: Red Hat Enterprise Linux BaseOS (v. 10)
affected:
  - enterprise_linux 6
  - enterprise_linux 7
  - enterprise_linux 8
  - openshift_container_platform 4
  - enterprise_linux_appstream_v_10
  - enterprise_linux_appstream_v_9
  - enterprise_linux_baseos_v_10
  - enterprise_linux_baseos_v_9
patched:
  - enterprise_linux_appstream_v_10
  - enterprise_linux_appstream_v_9
  - enterprise_linux_baseos_v_10
  - enterprise_linux_baseos_v_9
scores:
  nvd: 7.5
  vendor: 6.5
---

## Overview

rsync before 3.5.0 contains an algorithmic complexity vulnerability in the hash_search() function that allows a remote attacker to cause a denial of service by delivering a carefully constructed file list. A sender can exploit the quadratic-time worst-case behavior in hash lookups to exhaust receiver CPU resources with a modest number of crafted entries, causing a sustained denial of service.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Vendor advisories

- **RHSA-2026:67463** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 10), Red Hat Enterprise Linux BaseOS (v. 10) · released 2026-09-14 · [advisory](https://access.redhat.com/errata/RHSA-2026:67463)
- **RHSA-2026:67462** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 9), Red Hat Enterprise Linux BaseOS (v. 9) · released 2026-09-14 · [advisory](https://access.redhat.com/errata/RHSA-2026:67462)
- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat OpenShift Container Platform 4 · updated 2026-09-14 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-70453.json)